Hello guys,
i want to know how solder iron work?
There are 3 pins one with diode in wire path, why?

 

Perhaps the 'diode' is a temperature sensing device?

More info=better responses!

Best regards
HP

 

ADDENDUM:

Is the diode external to the assembly or is it internal and detected via continuity examination of the leads? (My last post assumed the latter)...

 

No pictures? Seriously?

 

Start with the obvious:

https://en.wikipedia.org/wiki/Soldering_iron

 

Sounds like the diode is to put the iron in half wave mode to keep it warm when its in the stand, then you short the diode out for full heat,